


expecting the unexpected

by Potrix



Category: Captain America (Movies), Iron Man (Movies), Marvel, Marvel Cinematic Universe, The Avengers (Marvel Movies)
Genre: Alpha Tony Stark, Alpha/Beta/Omega Dynamics, Alpha/Omega, Alternate Universe - Canon Divergence, Alternate Universe - Everyone Lives/Nobody Dies, Fluff and Crack, Getting Together, Happy Ending, M/M, Mpreg, Omega Bucky Barnes, Post-Captain America: The Winter Soldier, Pre-Relationship, Surprises, Timeline What Timeline, Unplanned Pregnancy
Language: English
Status: Completed
Published: 2020-01-06
Updated: 2020-01-06
Packaged: 2021-02-27 04:28:20
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,006
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/22131055
Author URL: https://archiveofourown.org/users/Potrix/pseuds/Potrix
Summary: “You think it’s a side effect of the serum?” Steve asks, mouth full of curly fries. Bucky throws a ketchup packet at him, which only makes Steve kick him under the table. “Maybe you were ever so slightly lactose intolerant before, but the serum heightened it? Like all our other senses?”“Pretty sure lactose intolerance isn’t a sense, buddy,” Bucky tells him with a roll of his eyes. He takes a long drink of his soy milk shake, which is actually much better than he’d thought possible before trying it for the first time. “‘Sides, I was eatin’ all kinds of shit while I was on the run an’ nothin’ ever bothered me much.”Steve nods, thoughtful. Then, a little forlorn, “Cheese, though.”
Relationships: James "Bucky" Barnes/Tony Stark
Comments: 55
Kudos: 880
Collections: 2019 WinterIron_Holiday_Exchange





	expecting the unexpected

**Author's Note:**

  * For [Zola9612](https://archiveofourown.org/users/Zola9612/gifts).



> My [2019 WIHE](https://winterironholidayexchange.tumblr.com/) gift for [Zola9612](https://archiveofourown.org/users/Zola9612). When I saw "surprise pregnancy/birth" as one of the prompts, I just couldn't resist. Obviously. 
> 
> Thanks to everyone who was part of the exchange this year. Happy reading to you all! ♥

_Feeling uneasy, itchy, too warm but also not nearly warm enough._

_Baring his teeth at the Alpha whenever he moves close, disappointment when the Alpha retreats again._

_Skin, damp and fever hot._

_Wet, slick, hot, so hot._

_Running._

_Snarling._

_Sharp teeth, against the Alpha’s neck, against his own._

_The ground, mossy soft, presenting for the Alpha, the Alpha moving in—_

Bucky shoots upright, panting, heart beating wildly. 

It takes him a moment to calm down enough to find his bearings, until he’s composed himself enough to make out the shapes of a dresser and an armchair in the dark, to feel the sheets under his fingers, to recognise the familiar scents; his bedroom, he’s in his bedroom. 

Breathing out shakily, Bucky lets himself fall back onto the bed, and closes his eyes again, rubbing trembling hands over his face. “Fuck.” 

Waking up disoriented has become depressingly familiar ever since escaping HYDRA, as have the nightmares and the dreams of half-obstructed, barely reachable memories. For the most part, Bucky is honestly relieved that he can’t recall much of his time as the Soldier, selfish as it may be. 

This, though? 

This is different. 

There are the quinjet’s logs, sure, and Bucky does remember the first several days after that portal had dumped them on some unknown planet halfway across the galaxy, but after that? All he has are flashes, glimpses, vague recollections of sounds and smells.

And it’s not like he can ask Stark about it, either. He’d brave the embarrassment of having to look the near stranger who’d fucked him through the half week of his heat in the eye—after a shot or two of vodka, maybe—if it wasn’t pointless. While Heat turns Omegas needy, reduces them to their most primal instincts, Rut makes Alphas downright stupid. Eager to please, protective, unable to think of anything but fucking and providing. 

Heat and Rut aren’t exactly periods of clear thinking and good decision making under regular circumstances, but, apparently, something in that damned planet’s atmosphere had made them both go even more caveman than usual. Bucky, even though he’d never admit it to the man in question, is glad it was Stark—witty, snarky, gorgeous, kind—there with him, and not one of the other Alphas on the team; even just thinking about Steve in that way makes him cringe, and Sam—well, just no. He’d never live that one down. 

After a quick glance at his phone, Bucky resigns himself to being awake for the day. He’s had trouble sleeping—more so than normally—for a few weeks now, never quite able to get comfortable even if he’s somewhere he usually feels safe. And then he tends to wake up at least once or twice a night, either sweaty and hot even with all the blankets kicked to the end of the bed, or to sprint to the bathroom as if he has a habit of chugging gallons of water before bed. 

There are several other people already up when Bucky shuffles into the kitchen, lounging around the table or sitting at the breakfast bar. Among them, surprisingly, is Stark. He’s one of the few Avengers who doesn’t permanently live at the Compound, and usually Bucky only ever sees him during meetings, missions, or the occasional team building exercise—if Steve and Stark bitching and yelling at each other while everyone else completes the actual tasks counts as such. 

But there Stark is, gaze following Bucky as he climbs up onto a stool. Bucky quirks an eyebrow at him in question. 

“Breakfast,” is all Stark says, sliding a plate with fresh, warm croissants across the bar. That is followed by a cup of hot chocolate—like fuck is Bucky going to force himself to drink coffee, now that it doesn’t even affect him anymore—and a bowl of neatly cut-up fruit. 

No one else, Bucky notices when he glances around the room, has croissants. 

“Uh,” he says, squinting a little at Stark. “Thank you?”

Stark waves it away like it’s nothing before taking a seat as well. He pulls out his tablet, completely immersed in whatever he’s doing a moment later. 

Bucky blinks, then shrugs to himself, and takes a sip of his hot chocolate. 

With nothing team related on the agenda until the afternoon, people scatter again once they’re done eating. Bucky considers his own options, eventually deciding on the gym. 

He hasn’t been back long enough to have a lot going on outside of Avengers business and spending time with Steve, and working out has always been a good distraction. And for the first half hour, it works, too. He hops onto one of the stationary bikes, building up a good sweat, before switching to the treadmill. 

He’s still good as he starts at a slow jog, but when he ups the speed to give himself a little bit of a challenge, there’s a sudden, sharp spike of pain low in his abdomen. Frowning, Bucky slows back down, hand pressed against the offending area. 

It only takes a couple of minutes to vanish completely, though, leaving him feeling fine again.

“Huh,” Bucky murmurs, “weird.” 

The rest of his workout is uneventful. 

Still, after his shower, with only a towel slung low around his hips, Bucky can’t help but stare at himself in one of the dressing room’s big mirrors. He looks normal, he thinks, the same as he did yesterday as far as he can tell. 

He cups his hands over his stomach, feeling the ever so slight curve to it. It’s barely noticeable, and Bucky hadn’t either, at first. He isn’t even sure when it had appeared. 

After Project Insight and then being on the run for months on end, left to his own devices without whatever HYDRA had regularly pumped into him to keep a superhuman’s metabolism going, Bucky’d lost a lot of weight fairly quickly. Mostly muscle mass, which he’s been trying to build back up ever since. He’s back in what the team doctors tell him is the norm for a man his age and height, but nowhere near where he was under HYDRA. 

Not that he particularly minds. He’s in good enough shape to do his job without having to nearly drive himself to exhaustion to maintain a physique no regular human could ever hope to achieve. 

It’s a good compromise, in Bucky’s opinion, between the Soldier and the starving kid he was back in the 30s. 

JARVIS tells him that Steve wants to know if Bucky’s up for lunch while he’s getting dressed, so they meet up for burgers and shakes at a tiny diner in Brooklyn that’s almost as old as them. It’s way past its prime, sort of dingy and always a little greasy, and Bucky absolutely loves it. 

“You think it’s a side effect of the serum?” Steve asks, mouth full of curly fries. Bucky throws a ketchup packet at him, which only makes Steve kick him under the table. “Maybe you were ever so slightly lactose intolerant before, but the serum heightened it? Like all our other senses?” 

“Pretty sure lactose intolerance isn’t a sense, buddy,” Bucky tells him with a roll of his eyes. He takes a long drink of his soy milk shake, which is actually much better than he’d thought possible before trying it for the first time. “‘Sides, I was eatin’ all kinds of shit while I was on the run an’ nothin’ ever bothered me much.” 

Steve nods, thoughtful. Then, a little forlorn, “Cheese, though.” 

Bucky rolls his eyes again. “Been through worse things than not bein’ able to eat cheese, Stevie. I think I’ll just about live.” 

They linger over root beers and pie until they have to leave to make the meeting. It’s mostly an update of how Natasha’s undercover operation is going, and once it becomes clear she’s more than fine, Bucky allows himself to zone out. 

Concentrating and focusing over long stretches of time has been somewhat of a struggle the last several weeks, but, Bucky supposes, that’s what happens when you can’t get a single, uninterrupted night of sleep. It hasn’t been an issue on missions so far, though, so he figures that keeping an eye on it is enough for now.

“—totally agree with Spangles over here,” Stark’s sarcastic voice brings Bucky back to the here and now, “great plan all around—”

“Oh, fuck you,” Steve replies good-naturedly, and then they’re off again. 

Bucky meets Sam’s eyes across the table, mouthing, “What can you do?” in answer to the face Sam pulls. 

It’s then that his body decides to act up again, another flare of pain making him gasp. 

Steve’s focus is on him in an instant, brows drawn together in concern.

But it’s Stark who lays a hand on Bucky’s shoulder, squeezing gently. “Barnes? You all right?” 

It’s already more of an ache than actual pain now, like an overexerted muscle, so Bucky nods, albeit somewhat hesitant. “Yeah, think so. Probably just a cramp or somethin’.” 

Stark watches his face for a moment longer before smiling slightly. “If you’re sure,” he says, patting Bucky’s shoulder once again. 

He moves out of the way when Steve nudges him, not satisfied until he can check on Bucky himself. It’s unusual enough that Steve hadn’t claimed the seat next to Bucky, the overprotective punk. Bucky lets Steve fuss over him for a few minutes before batting him away with more reassurances that he’s fine. 

Which—is mostly true. 

He doesn’t hurt anymore, not exactly, but the ache is still lingering, like an old bruise. It’s not entirely pleasant, but also not bad enough that Bucky doesn’t feel up to joining everyone else in the living room.

Just in case, though, he braces himself for another wave. And it does come, some thirty minutes later, but this time around, Bucky’s prepared enough to hide what’s happening. He accepts the fact that something’s wrong when it happens again, twenty minutes later, then again, then not even ten minutes later, a clear pattern.

Then the next spike feels like it rips right through him, and Bucky can’t hold back his groaned, “Oh, shit.” 

Every single head in the room turns to stare at him. 

Defensively, Bucky says, “I’ve had worse.” 

Stark gives a pointed look at his arm. “Hate to disappoint you, Snowflake, but that’s not exactly saying much.” 

Steve is wide-eyed, half a step away from literally wringing his hands, but then Banner crouches next to Bucky, hand hovering over Bucky’s stomach. “May I?” When Bucky nods, he pushes up Bucky’s shirt, fingers careful as they press and push where Bucky tells him it hurts. “Can you describe the pain?”

Bucky tries, as best as he can, while Banner presses and prods at him. He’s frowning when he sits back. “There’s no way to be entirely sure, but it feels like there’s some kind of foreign mass or object.” 

“Well,” Stark stands, claps his hands together, “I think it might be time to move this show somewhere more appropriate.” 

A few minutes and one more cramp that leaves him almost breathless later, Bucky’s lying on a hastily emptied desk in the Compound lab, bare save for a sheet covering his private bits. Banner and Stark are flitting around him, talking science Bucky has no chance of understanding to each other and the A.I., while Steve hovers nervously by Bucky’s head. 

Bucky tenses when Stark steps up to him with some blinking contraption in hand. He closes his eyes, breathes in deeply, trying to relax, then jumps when Stark puts a hand on his chest.

“It’s painless,” he promises, “just a series of scans. If that doesn’t get us anywhere, we’ll draw some blood, but one step at a time, okay?” 

At Bucky’s nod, he holds the scanner to hover over Bucky’s midsection, waiting until it beeps. He moves it a few inches, waits for another beep, then repeats the process several times. He pauses when Bucky’s hit by another bout of pain that has him grit his teeth. 

“I think that’s enough,” he says, and Banner nods, leaning in close to look at the scanner’s readings. 

Banner’s eyebrows raise slowly as he reads, while Stark’s face scrunches up in confusion. 

“Well?” Steve grunts. 

“That can’t be right,” Stark murmurs, mostly to himself, tapping a few keys on the scanner. “It’s not possible—”

“The results don’t lie, Tony,” Banner cuts in, taking the scanner from him. “And we’ve all done and seen impossible things before.” 

“Male Omegas are a remnant of an era when humanity was on the brink of extinction,” Stark argues, hands on his hips, “with the same biological equipment but sterile, there hasn’t been a case of male Omega pregnancy in longer than we can reliably reconstruct, it’s—” 

“They told me I’d never have kids,” Steve says, quietly. Bucky reaches out to close a hand around his wrist in support. It’s always weighed on Steve, he knows, been a hard pill to swallow that he won’t even have the chance to be a father one day. “I’m perfectly able to have them now, though, according to every test we’ve done since I was found in the ice.” 

Bucky had not know that. Bucky does know what Steve’s trying to tell them, though. “You’re sayin’ I’m—I’m pregnant?” 

“In labour, I’d wager,” Banner agrees.

Without his permission, Bucky’s eyes seek out Stark’s. Stark’s widen at the contact, full of understanding. 

“Am I—”

“Yeah.” 

The tense, awkward silence that follows is interrupted by another contraction. 

Banner breaks it with, “I vote we call in an actual, medical doctor.” 

After that, things are a blur. Bucky is moved to the medical wing, one arm around Steve’s shoulders, the other clutching Stark’s arm as they half drag him through the halls, Banner hurrying ahead to prep as much as he can until the professionals arrive. They help him up onto a gurney, Stark tucking the sheets snugly around him again with shaking hands. 

Before he can pull back completely, Bucky snags one of his hands, gripping it tightly. Stark doesn’t hesitate to squeeze back. 

Steve looks like he wants to protest when the medical team finally arrives, and the surgeon tells him everyone but the fathers—holy fuck, fathers—will have to wait outside. But then he just fixes Stark with an intense look and a quiet, “Take care of him.” 

Stark is watching Bucky, not Steve, when he promises, “I will.” 

Without Bucky having to ask, Stark stays as close as he’s able to. He also narrates everything that’s happening, which makes the amount of needles and instruments Bucky can see out of the corner of his eye at least somewhat less terrifying. 

Whatever anesthesia they give him makes him kind of woozy, which makes Stark chuckle softly, smiling down at him. “You look high as a kite.” 

“Feel like it,” Bucky hums, smiling back dumbly. 

The surgery itself is over quickly—or maybe it’s just Bucky’s drugged up brain, unable to keep track of time—but it feels like mere minutes of Stark murmuring comforting nonsense to him, stroking his thumb over the back of Bucky’s hand he’s still holding, before there’s a loud, angry-sounding wail. 

“Congratulations,” one of the nurses says, eyes crinkled, definitely smiling behind his mask, “it’s a boy. Looking healthy, but we’re just going to clean him up, give him a quick check-up to make sure.”

“Go,” Bucky slurs, nudging Stark. When Stark hesitates, he adds, “Please? Make sure he’s okay?” 

Stark breathes out harshly, but he nods. “Yeah,” he says, pressing his forehead against Bucky’s for a moment. “Yeah, I can do that.” 

Bucky drifts, once Stark leaves, suddenly exhausted. He hears the surgeon and nurses talking to him, watches them lazily until his eyes start to droop, until it feels like too much of an effort to keep them open any longer.

Stark has the baby. Their baby. Stark will take care of it. Of them. It’s going to be fine. 

Everything’s going to be fine.

*

Bucky blinks awake to soft humming, a quiet, slow melody he doesn’t recognise. 

His bedroom, he notices happily, instantly more at ease. There’s an IV needle stuck in the back of his hand, and he feels sore all over but otherwise fine. Floaty. Still tired, though. 

He yawns loudly, which makes the humming stop abruptly. 

“Good morning, sleepyhead,” comes Stark amused voice, followed by the man himself perching on the edge of Bucky’s bed. “You’ve been out for a while, but there’s someone here who really wants to meet you.” 

And just like that, Bucky’s wide awake.

“Where is—”

But Stark is already bending down, slow and careful, and Bucky quickly holds out his hands to accept the wriggling bundle into his arms. The baby is awake, if only barely, eyes closed almost all the way, tiny mouth open ever so slightly. 

“So small,” Bucky marvels, and it comes out all chocked-up, “he’s so small.”

He brings the baby up to lie against his shoulder, pushing his nose into the downy-soft fuzz on his head to scent him. He smells like something milky, formula probably, fresh and warm and like Bucky, Like Stark, as well. 

Stark, who’s sitting close enough to be pressed against Bucky’s side. Who smells of contentment, like he’d been crying recently—happy, though, no sadness anywhere—and, faintly, working its way past the rest, arousal. 

Bucky snorts, kisses the baby’s wrinkled forehead. “You for real right now?” 

Stark shrugs, unapologetic. “There’s a hot, mostly naked guy holding my brand new baby. Can you really blame me?” 

Not really. Still, “Buy me dinner first,” Bucky jokes, but Stark doesn’t laugh. 

Instead, he puts his hand over Bucky’s on the baby’s back, expression more serious than Bucky’s ever seen it before when he says, “I will. If you let me.” 

Bucky pretends to consider, hiding a pleased smile against the top of the baby’s head. “I’ll think ‘bout it.” 

Going by Stark’s brilliant smile, he definitely knows what that means.

**Author's Note:**

> Tony: I have the sudden urge to rub myself all over Bucky and be as close to him as possible and feed him and protect him, hahahaha, totally normal, right? 
> 
> Go check out my other [work](http://archiveofourown.org/users/Potrix/works), or come over and say hi on [tumblr](http://potrix-the-queerschlaeger.tumblr.com).


End file.
